Insulator



May 12, 194". A. NEUBAUER INSULATOR 'Filed May 20, 1959 Ely.1

fm/en for:

6101's IYQUZIGUGI" Patented May 12,1942 I msumroa Alois NeubauenBerlin, Germany, assignor to 0.

- Lorenz Aktiengesellschaft, Berlin-Tempelhof,

Lorenzweg, Germany, a company Application May 20, 1939, Serial No. 274,797

Germany May 23, 1938 o 4 Claims.

This invention relates to electric insulating devices, and more specifically, although not exclusively, to insulators of the type applicable to aeroplanes for insulating the antenna lead-in conductor from the metallic structure of such vehicles.

It is a necessary requirement in aeroplanes having radio direction finding equipments mounted thereon to provide a perfect electric insulation between the'antenna lead-in of such equipment and the metallic structure of the vehicle since the antenna is maintained at high potentials. Considerable difiiculties have been encountered in maintaining the isolation between the heretofore known dielectric insulators and the antenna lead-in conductor at an optimum value, specifically when the airplane flies at major heights where the temperature is many degrees below zero, because of the fact that waste water is subject to vaporization on the inner flange of the insulator, and to a conversion into ice on the outer flange thereof, which phenomena nullify the effectiveness of the insulation.

It is an object of this invention to overcome the above mentioned difficulties by maintaining the insulator of an antenna lead-in conductor of an airplane at an enhanced temperature which reliably eliminates each occurrence of the afore-, mentioned deleterious effects.

My invention will be understood from the following description taken in conjunction with the accompanying drawing, in which Fig. 1 is a front elevation of the inner flange of an antenna lead-in insulator according to my invention, while Fig. 2 is a cross sectional view through the device embodied in Fig. 1.

Referring to the figures, the reference B denotes a wall or similar part of an aeroplane in which an insulator C is fixedly mounted. The inner surface of the flange-shaped portion of this insulator is provided with a spirally cut groove in which an electrically heated member H of similar shape is embedded. This, member when heated maintains the whole insulator at a properly enhanced temperature which reliably ensures perfect insulation between the antenna lead-in conductor A and the aeroplane structure or framework B, since theaforementioned detrimental effects' cannot be involved.

The heat current supplying circuit is preferably provided with means for adjusting the temincrease in excess to a predetermined permissible value.

. What is claimed is:

l. A lead-in insulator for leading-in an antenna through an exterior wall of an aeroplane which comprises an insulating body provided with a disc-like flange whose periphery is shaped to fit against a generally flat exterior wall, shaped to present a generally fiat overall surface on the exterior side of said periphery, pierced by an aperture suitable for the passage of a lead-in wire, and formed with an extended surface generally parallel to said generally flat exterior surface but on the interior side of saidperiphery, and an electric heater disposed wholly on the interior side of said periphery and in proximity to said extended surface for artificially raising the temperature of both the interior and exterior surfaces of said insulator.

2. An insulator according to claim 1 wherein said insulating body further comprises an in-' tegral sleeve surrounding saidaperture and extending normal to said disc-like flange on the interior side thereof.

3. In an aeroplane having a'framework comprising an enclosure, an opening in said framework, an insulator comprising a flange-shaped,

dielectric body shaped to fit said opening with the exterior surface of said body substantially flush with the exterior of said framework, a spiral cavity on the inner surface of said disc, an electric heater disposed in said cavity for heating said disc and preventing the formation of ice on the exterior surface thereof at high altitudes, an opening in said body to receive an antenna lead in conductor and a tube of insulating material connected with said opening and depending below said heater.

' 4. In an aeroplane having a framework comprising an enclosure, an opening in said framework, an insulator comprising a disc-shaped dielectric body with one surface flattened adapted to fit.said opening with the flat surface thereof substantially flush with the exterior of said framework, a flange formed on the edge of said disc overlapping the edge of said framework, a spiral cavity on the inner surface of said disc and said flange, an electric heater disposed in said cavity for heating said disc and preventing the formation of ice on the outer surface thereof at high altitudes, an opening in said disc, and an antenna conductor disposed in said opening insulated from said framework and said heater.

ALOl'S NEUBAUER. 

